Anionic polymerization

ABSTRACT

A novel process for polymerization or copolymerization of monomers is described, according to which the reaction is carried out in the presence of an anionic initiator and a macroheterocyclic complexing agent of formula   IN WHICH: EACH R1 is a hydrogen atom, a hydrocarbon group or an alkoxycarbonyl group, or the two R1 together can form a group of the general formula:   THAT IS TO SAY FORMING A THIRD BRIDGE BETWEEN THE TWO NITROGEN ATOMS IN THE MOLECULE, A is a hydrocarbon group, D is an oxygen or sulphur atom or a hydrocarbon group, with the proviso that at least two of the groups D are oxygen or sulphur atoms and that, if each R1 is hydrogen, a hydrocarbon group or an alkoxycarbonyl group, one of these two groups D is oxygen or sulphur and the other is oxygen, N AND P ARE INTEGERS RANGING FROM 1 TO 3, AND M IS 2 OR 3.

Lehn et al.

[ 1 ANIONIC POLYMERIZATION [75] Inventors: Jean-Marie Lehn, Strasbourg;

Francois Schue, Lutzelhouse; Sylvie Boileau, Paris; Bernd Kaei'npf, Strasbourg; Alain Andr Cau, Chateauneuf sur Loire; Jean Robert Moinard, Vert le Petit; Serge Fernand Raynal, Villejuif, all of France [73] Assignee: Societe Nationale des Poudres et.

Explosifs, Paris, France [22] Filed: Sept. 26, 1973 [21] Appl.No.: 401,119

[30] Foreign Application Priority Data Oct. 3, 1972 United Kingdom 45482/72 July 30, 1973 United Kingdom 36257/73 1 June 17, 1975 [56] References Cited UNITED STATES PATENTS 3,159,647 12/1964 Poppelsdorf 260/946 3,451,988 6/1969 Langer, Jr 260/946 3,536,679 10/1970 Langer, Jr 260/831 Primary ExaminerMelvyn I. Marquis Attorney, Agent, or Firm-Bucknam and Archer [57] ABSTRACT A novel process for polymerization or copolymerization of monomers is described, according to which the reaction is carried out in the presence of an anionic initiator and a macroheterocyclic complexing agent of formula in which:

each R is a hydrogen atom, a hydrocarbon group or an alkoxycarbonyl group, or the two R together can form a group of the general formula:

[52] US. Cl. 260/63 R; 260/821; 260/855 L; 260/85.7; 260/883 R; 260/887 R; 260/887 F; 260/895 R; 260/9l.1 A; 260/928 R;

51 Int. Cl C08g 1/12 58 Field of Search 260/63 R, 82.1, 85.5 L,

260/857, 88.3 R, 88.7 R, 88.7 F, 89.5 R, 91.1 A, 92.8 R, 93.5 R, 94.2 M, 94.4, 94.9 R, 94.6

27 Claims, N0 Drawings ANIONIC POLYMERIZATION The present invention relates to the anionic polymer ization of monomers by basic initiators in an organic solvent medium.

The reaction mechanism of anionic polymerization comprises three main steps:

a. an initiation step in which the monomer is activated by attachment of the anion provided by the initiator to a molecule of the monomer,

b. a propagation step in which growth of the chains in which:

each R, is a hydrogen atom, a hydrocarbon group or an alkoxycarbonyl group, or the two R together can form a group of the general formula:

/A M K.

takes place by reaction of the activated molecule with a new monomer molecule and so on, and

c. an interruption step in which the growth of the 'chains is stopped through disappearance of the activated centres.

The growth of the chains is uniform; branched chains, due to growth of a side chain on the main chain, are rare and sometimes impossible so that the regularity of the structure of the polymers obtained by anionic polymerization often imparts noteworthy physical properties to the polymers.

The influence of the polarity of the medium on the initiation reaction and growth reaction is very great. In the case of the propagation reaction, the speed is greatly increased in polar media. This is due to the increase in the possibilities of solvation of the ion pairs by the solvent, which can increase their possible charge separation and to the effect of the dielectric constant, which considerably increases the dissociation into free ions. Hence, the growth reaction is strongly influenced by the thermodynamically distinct species which are in equilibrium with one another.

According to the present invention, anionic polymerization initiators are used in combination with certain macro-heterocyclic complexing agents. These complexing agents not only increase the basic character of the anionic polymerization initiators but also have a considerable influence on the species which are present.

The use of these complexing agents has the following advantages: polymers of high molecular weight can be obtained; the range of solvents which can be used is increased; certain monomers which have hiterto been difficult to pothat is to say forming a third bridge between the two nitrogen atoms in the molecule,

A is a hydrocarbon group,

D is an oxygen or sulphur atom or a hydrocarbon group, with the proviso that at least two of the groups D are oxygen or sulphur atoms and that, if each R is hydrogen, a hydrocarbon group or an alkoxycarbonyl group, one of these two D groups is oxygen or sulphur and the other is oxygen,

n and p are integers ranging from 1 to 3, and m is 2 or 3.

The hydrocarbon groups represented by A and D preferably have 2 to 12 carbon atoms and are especially: straightchain or branched alkylene and alkenylene groups with 2 to 8 carbon atoms, such as the ethylene, propylene, butylene and hexylene groups and their unsaturated analogues; cycloalkylene groups such as cyclohexylene and cycloheptylene groups and their unsaturated analogues; corresponding cycloalkylenealkyl or dialkyl groups such as cyclohexylene-dimethyl, and aromatic groups such as phenylene and phenylenealkyl or dialkyl groups preferably phenylene-dimethyl. The groups A which are adjacent to the nitrogen atom preferably have an aliphatic portion attached to N.

The hydrocarbon groups represented by R preferably have 1 to 12 carbon atoms, and compound especially straighbchain or branched alkyl groups with 2 to 8 carbon atoms. Other typical examples are cycloalkyl, aralkyl and aryl groups. The preferred alkoxycarbonyl groups represented by R, in the general formula (I) are those with up to l0 carbon atoms.

The preferred macro-heterocyclic compounds are those with the typical configurations shown below:

\EO /-A m ct! CH2 CH c11 N A l 2 P cn CH2 CH2 cs c21 L i 5 \A E or 0 /A\o/ l0 N A A A N or O\A/ o o cn CH2 l f CH CH2 N K8 or o o o CH2 CH2 CH2 CH2 A A o \o N O -A/S --A N A s s A \A A CH2 cH l CH2 CH2? s' p N A A 5 AS N -CH -CH CH CH 3 s 2 2 2 2 A/ \A/ \A O p Examples of macro-heterocyclic compounds are those in which: 2- }E 2- fl n\ A==--CH -CHR A=CH -CHRCH or 0 N -CHRCH -CH or EO\ 40 cn -cn CH CH n A fcn -cn g cn -cn and R is a hydrocarbon radical.

More particularly, the preferred macro-heterocyclic and n, and p are integers from 1 to 3 and m is 2 or 3. compounds used in the present invention are repre- Typical examples of these compounds are the followsented by the following general formula: ing:

/CH2 cn cn ca cu cn f 0 CH2 cud- CH CH CH2 ca H H CH 2 C 2\EO/c 2 (II) R ---N N R l o l cn CH cu cHg in whi h; wherein n and p are integers from 1 to 3 and m is 2 or the two substituents R together represent one of the 3, especially: following chain links forming a third bridge between in the case of m=2, n=1 and p=l the two nitrogen atoms of the molecule l,l0-diaza-4,7,l3,18-tetraoxa-bicyclo[5,5,8]eicosane,

l,10-diaza-4,7,l3,16,21,25-hexaoxa-bicyclo[8,8,9-

5 6 v referred to as compound [21 l] in the case of m=2, n=2 and p=l 1 I l,l0-diaza-4,7,l3,16,2l-pentaoxa- I I i bicyclo[8.8,5]tricosane, referred to as compound j" N in the casee of m=2, n=2 and p=2 I 1, l O-diaza-4,7, l 3,l 6,21 ,24-hexaoxa-bicyclo[ 8,8,8- ]hexacosane, referred to as compound [222] in the case of m=3, n=2 and p=2 O 1,l3-diaza-4,7,l0,l6,l9,24,27-heptaoxabicyclo[8,8,ll]nonacosane, referred to as compound r\ F'" \3 [322] NI O N in the case of m=2, n=2 and p=0 O (2) N 4. i/ N O O l,7,l6,22-tetraaza-4,l0,l3,19,25,28,33,36,4l,44-

. decaoxatricyclo[20.8" .8" .8"-' ]hexatetracontane,

\ referred to as [T 0] These macro-heterocyclic compounds have an ex- 1,10-diazal 3,16,21 ,24-tetraoxa-bicyclo[8,8,8]hexf i ability 9 Stable acosane referred to as Compound [220] ible cations. The bridges between the nitrogen atoms 25 form, amongst themselves, a cage in which the cation is trapped (whence the name cryptate given to b these complexes). g The capacity to form complexes and the stability of N the complexes formed depend on the arrangement of ,O o the heteroatoms or groups surrounding the cation and V on the relative diameters of the rings and of the cation.

It results in a characteristic selectivity between cations and macro-heterocyclic compounds which is demonstrated in the present invention.

Each macro-heterocyclic molecule is capable of forming a complex with a cation. The value of the charge on the cation has no influence. These cations N are generally inorganic cations. The formation of cryptates has been established with 40 the macro-heterocyclic compounds defined above and the stability constants have been measured. The results ]heptacosane, referred to as compound [22p] 35 are summarised in Table 1 below.

TABLE I Stability constant of cryptates (Log Ks) 65 tors which are active even under conventional polymerization conditions but also makes it possible to use 1,lO-diaza-4,7, l3',16-tetra0Xa-2l .24-dithia-bicynew initiators which have hiterto proved inactive in this clo[8,8,8]hexacosane, referred to as compound [402$] type f polymerization cation Macrocyclic* compound Li Na K+ Rb Cs Ca Sr Ba Compound [2l l 1 2.6 2 2 2 2.8 2 2 2211 2.5 |'s 3 3.9 2 2 II] 1% 6.3 J 2221 2 3.8 E2] [51 2 4.4 EL

solvent H2O. temperature: 25C 0.lC.

l,l0-diaza-4,7,l3,l6,2l,24-hexaoxa-5,6-benzo- In organic solvents, the stability of the cryptates is bicyclo[8,8,8]hexacosane, referred to as compound better still; thus, for compound [222], which preferen- [22B] tially complexes the potassium cation, the logarithm of f the stability constant is greater than 9 in benzene. J The use of the macro-heterocyclic complexing agents (5) defined by the formula I not only makes it possible very markedly to improve the activity of the anionic initia- O O In fact, such complexing agents display noteworthy complex-forming properties towards metal cations, especially cations of group I and II of the periodic classification of the elements, provided by anionic initiators; these metal cations become inserted in the intramolecule cavities of the said complex-forming agents, with the formation of cryptates.

As a result, the reactivity of the corresponding anions provided by the said initiators is very markedly increased due to the formation of non-intimate ion pairs and free ions.

In general terms, the macro-heterocyclic compounds of the general formula I can be used for the polymerization of all monomers capable of polymerizing by the conventional anionic polymerization process, and, in particular, of vinyl monomers, mono-olefinic monomers, diene monomers and heterocyclic monomers of the following types:

A. Mono-olefinic monomers and vinyl monomers of 0 the general formula:

3 R \R (A) wherein R R R and R, can be defined as follows: R,=R =R =R =l-l (as in the case of ethylene) 0 R =R =R =H and R,,= 3

-CHCH CH 6H 5 (as in the case of 4-methyl-l-pentene) R =R =R =H, R

wherein X can be:

H (as in the case of styrene) Cl or Br in the ortho, meta or para positions (as in the case of chlorostyrene or bromostyrene) OCH; (as in the case of p-methoxystyrene) and C(-CH (as in the case of p-tertiary butylstyrene) R =R2 H, R3=CH3, R4:

(as in the case of a-methylstyrene) RI=R2=R3=H1 4 8 R being an alkyl or cycloalkyl radical'(as in the case of alkyl or cycloalkyl acrylates) R =R =H, R =CH with R =C' E N (as in the case of methacrylonitrile) I r or R (L'COR' R being an alkyl or cycloalkyl radical (as in the case of alkyl methacrylate or cycloalkyl methacrylate) R" alkyl (as in the case of the vinyl ketones) B. Diene monomers of the general formula wherein R R R R R and R can be defined as follows:

butadiene) R =R =R =R =R =H and R can be a substituent such alkyl (as in the case of 2-alkyl-l ,3-butadienes) or aryl (as in the case of 2-aryl-l,3-butadienes) or chloro (as in the case of 2-chloro-1,3-butadiene) R =R =R =R =R =H and R can be substituent such alkyl (as in the case of l-alkyl-l ,B-butadienes) or aryl (as in the case of l-aryl-l,3-butadienes) or nitrile (as in the case of l-cyano-l ,3-butadiene) or nitro (as in the case of l-nitro-l,3-butadiene) R =R =R =R =H and R =R =CH -(as in the case of 2,3-dimethyl-l ,3-butadiene) R =CH and R =R =R =R =R and can be either H (as in the case of 1,3-pentadiene) and/or alkyl (as in the case of alkyl-1,3-butadiene) (as in the case of 1,4-diphenyl-1,3-butadiene).

in the case of 1,3-

C. Heterocyclic monomers being a hydrogen atom or an alkyl or cycloalkyl or aryl radical. the cyclohexene sulphide or of the general formula n being an integer from 1 to 4 an in particular B-propionlactone, e-caprolactone and pivalolactone and siloxanes such as hexamethylcyclotrisiloxane and octamethylcyclotetrasiloxane.

The compounds of the general formula I are used for the anionic polymerization of the monomers in the presence of basic initiators which are chosen from amongst the following metals, salts and metal complexes:

metals of groups I and ll (in particular Li, Na, K and hydroxides of metals of group I (in particular KOH);

alcoholates of metals of group I and ll, it being possible for the alcohol to be an alkanol or cycloalkanol or an aromatic alcohol (especially alkali metal tert.- butylate, alkali metal tert.-amylate and alkali metal namylate);

amides of metals of groups I and II of the type N} M n it being possible for R and R to be hydrogen or an alkyl, cycloalkyl or aryl radical, whilst M is a metal of group I and ll (especially sodiumor potassiumcarbazyl) M being the valency of the metal compounds MX,,, wherein M represents a metal of group I or II, as well as the corresponding subgroups, n being the valency of the metal, whilst X can be a thiocyanate or acetate group (especially potassium thiocyanate, and potassium acetate).

monofunctional and difunctional organo-metallic derivatives of the type RM, wherein M represents a metal of group I or II and R can be an alkyl, cycloalkyl or aryl radical (especially n-butyl lithium, t-butyl lithium);

aromatic complexes of the metals of groups I and II (especially naphthalene-sodium, naphthalene-lithium and naphthalene-potassium); and

living monofunctional and difunctional oligomers and polymers (especially oz-methylstyrene K or -Na, l,l-diphenylethylene-Na. propylene polysulphide-Na and polystyrene-Li).

The value of the living polymer is that it is much more stable than the original initiator and allows better control of the polymerization as well as of the manufacture of the copolymers.

The polymerization or copolymerization according to the invention is carried out in non-polar or slightly polar organic solvents, especially:

linear andcyclic saturated hydrocarbons,

aromatic hydrocarbons,

linear and cyclic ethers such as dioxane, dimethoxymethane, tetrahydropyran, dimethoxyethane and tetrahydrofuran.

The non-polar or slightly polar organic solvents used according to the present invention are preferably organic solvents of dielectric constant not exceeding 10. These solvents have the advantage over solvents of higher polarity that their cost price is lower, that they are safer to use and that they are more easily purified (separation of the various fractions and retention of the initial purity).

Table II gives some typical examples of solvents used,

TABLE II Dielectric Temperature Solvent constant C Hexane 1.879 25 Heptane 1.924 20 Cyclohexane 2.023 20 Dioxan 2.209 25 Benzene 2.275 25 Toluene 2,379 25 Dimethoxymethane 2,645 20 Ethyl ether 4.335 20 Tetrahydropyran 5 .61 25 1.2-Dimethoxyethane 7.20 25 Tetrahydrofuran 7.5 8 25 These solvents can be used individually or as mixtures.

According to the present invention, polymerization is carried out in vacuo or in an inert gas atmosphere which in practice is nitrogen or argon,

According to a preferred form of carrying out the process of the present invention, the anionic initiator is first reacted with the complex-forming agent of the formula I in a non-polar or slightly polar solvent medium.

This reaction is very fast under normal temperature and pressure conditions or in vacuo and gives an activated complex in which the metal ion provided by the initiator is inserted in the cage consisting of the macroheterocyclic compound of the formula I.

Preferably, the compound of the formula (I) to be used depends on the radius of the metal cation of the anionic initiator.

The complex-forming agent is used in an at least equimolar amount and preferably in excess relative to the anionic initiator.

The activated complex thus obtained is now used for the polymerization of monomers under the working conditions enumerated above.

As has already been mentioned previously, it is possible, by virtue of the use of the complex-forming agents defined by the formula I, to employ new initiators, which makes it possible to attach valuable functional groups to one of the ends of the macromolecule. Thus it is possible to envisage the initiation (of the polymerization) of ethylene oxide or propylene sulphide by salts such as potassium thiocyanate dissolved in tetrahydrofuran. and that of isobutene sulphide by potas sium acetate in benzene solution.

The present invention also relates to the preparation and use of new initiators for anionic polymerization which can be used in solvents of very low dielectric constant. Thus it is possible to envisage the preparation of solutions of metals of group I, in nonpolar solvents, as well as the organic complexes derived therefrom.

Hitherto, since the metals were insoluble in nonpolar solvents or very slightly soluble in slightly polar sol vents (such as tetrahydofuran or dioxan), the polymerization reaction could only be carried out in a heterogeneous medium, thus giving rise to polymers of relatively broad molecular weight distribution. Furthermore, in the case of copolymerization these systems resulted in a not insignificant percentage of homopolymer.

The action of the macro-heterocyclic compounds I is to allow the metals to be dissolved in non-polar solvents as well as in slightly polar solvents.

The solutions thus obtained are very active as initiators of the anionic polymerization of the monomers described in the present invention.

Table 111 gives some examples of initiator solutions.

The solutions of dissolved metals described in the present invention are obtained by adding a given amount of macro-heterocyclic compound 11 to a metal film or to a finely divided metal in an organic solvent.

This preparation can be carried out at ambient temperature and at ordinary pressure as well as under low pressure in the case of benzene and of dioxan and at a low temperature if the solvent permits this (for example tetrahydrofuran and toluene); the solutions obtained being more stable at a low temperature.

Before use, these solutions are filtered so as to remove the undissolved excess metal.

Furthermore, the value of initiation by complexes formed between aromatic hydrocarbons and alkali metals is considerable; in fact, as this initiaton takes place by electron transfer, it leads to the formation of difunctional polymers. However, their use has been limited to a restricted number of solvents because they cannot be prepared in solvents of low dielectric constant; these compounds have in general been obtained by reaction between an alkali metal and a polycyclic hydrocarbon in certain ethers (tetrahydrofuran, dimethoxyethane or di ethyl ether), these latter permit solvation of the cations.

The macro-heterocyclic compounds make it possible to prepare these initiators easily even in non-polar solvents.

In order to do this, it is possible to use the solutions of metals described above in the presence or absence of the metal film or finely divided metal; in the former case, the organo-metallic complex forms simultaneously in the solution (homogeneous medium) and on the film (heterogeneous medium); in the latter case.

the reac 1 takes place solely in a homogeneous medium.

The aromatic compound must have a sufficient electron affinity that it captures the peripheral electron of the alkali metal to give an ion radical; the capture of a second electron leading to the formation of a dicarbanion. This aromatic compound is preferably biphenyl, naphthalene, phenanthrene, pyrene and anthracene.

The present invention also relates to the preparation, in non-polar solvents, of initiators such as the living oligomer of ot-methylstyrene or of 1,1- diphenylethylene; these initiators have hitherto only been obtainable in a polar medium.

The complexes thus obtained are excellent initiators of the anionic polymerization.

The preparation of naphthalene-sodium and of naphthalenepotassium in a benzene medium, in the presence of a macro-heterocyclic compound, is described below.

The solution of alkali metal in benzene or another solvent is prepared in the same way as described previously.

The sublimed napthalene is added to this solution, in excess or in equimolecular amount relative to the macroheterocyclic compound. The latter immediately assumes a characteristic green coloration of the ion radical of naphthalene. Spectroscopic measurements in the ultraviolet and visible have confirmed that the ion radical corresponding to the aromatic hydrocarbon used is indeed formed.

The present invention is illustrated by the nonlimiting examples which follow:

EXAMPLE 1.

ture:

1,4-addition (total) 24% 1.2-addition 307! 3.4-addition 46% Degree of unsaturation Intrinsic viscosity [1;]dl/g 5.99 (toluene. 50C. FICA viscometer) EXAMPLE 2.

Polymerisation of isoprene in the presence of the sodium-compound [221] initiator system dissolved in benzene.

A film of sodium was formed in a very high vacuum and a certain amount of benzene (30 cm) was then allowed to come into contact with the (sodium) mirror. The addition ofthe compound [221] (2 10" mol) was accompanied by the appearance of a coloured solution, with disappearance of the metal film. 2.5X10 mol of isoprene were added to this solution.

The solution was deactivated after 48 hours and a liquid polyisoprene of number average molecular weight Mn 2,000 (determined by means of a membrane osmometer of the MERCROLAB type) was obtained.

EXAMPLES 3 to 24 EXAMPLE 25.

Polymerization of ethylene oxide in the presence of the sodium-compound [222] initiator system in solution in tetrahydropyran.

The solution of initiator was prepared by adding 1,03. 10 mol compound [222] to 28 cm of-tetrahy- "dropyran which covered a very thin film of metallic sodium. The metal dissolved and the solution assumed a dark blue colour. The infra-red spectrum of the solution showed achar'acteristic band at 1,250 cm. 4.10

mol of ethylene oxide were added to this solution. The

solutiondecolorised, and set solid, instantaneously.

EXAMPLE 26.

solution was deactivated by adding methanol.

The polymer was precipitated in methanol and dried to constant weight.

The yield was 100%. Mp 6,510"

Intrinsic viscosity [1 4.23 dl/g(tluene, 50C) gyration radius 2 000 A EXAMPLE 27.

' Polymerization of styrene at low temperature in a tetrahydrofuran medium over a film of lithium in the presence of compound [21 l i '4.4 10 mol of compound [211] were added to 30 cm of tetrahydrofuran. covering a film of lithium, under a high vacuum. 2X10 mol of styrene were then added thereto at '80C. The instant appearance of a yellow colour and an increase in viscosity were observed/After 5 days polymerization the solution was deactivated by adding methanol. The polymerization yield was 100%. Mp 1.6.10

Viscosity [nldl/g 1.49 in toluene at 50C Gyration radius 800 A EXAMPLE 28.

Polymerization of isoprene in the presence of the metallic potassium-compound [222] initiator system in a benzene medium.

lsoprene (representing 3X10 mol) were added to a solution of 12.5 mg (representing 3X10 mol) of compound [222] in 30 cm of benzene covering a film of metallic potassium.

The polymerization was initiated instantly at the surface of the metal film.

The polymer obtained had the following micro structure:

Degree of unsaturation 97.5% 1,4-addition (total) 37% 3,4-addition 36% l,2-addition 27% A great increase in 1,4-trans-addition, 3,4-addition and 1,2-addition compared to what was observed in the absence of the complex-forming agent was noted.

EXAMPLE 29.

Polymerization of isoprene initiated by potassium in a tetrahydrofuran medium in the presence of compound [222].

5X10 mol of compound [222] dissolved in 53 cm of tetrahydrofuran were added to 10 mol of potassium hydroxide dried under a high vacuum. 4.2Xl0 mol of isoprene were added to this solution at 25C. The polymerization was instantaneous, with a yield of percent.

The NMR analysis carried out on this polyisoprene gave the following results:

1,2-structure: 28% 3,4-structure: 60% 1,4-structure: 12%

EXAMPLE 30.

Polymerization of hexamethylcyclotrisiloxane initiated by KOH in the presence of compound [222] in benzene.

3.15 mg of KOH (representing 5.6Xl0' mol) previously dried by heating in vacuo for 6 hours were introduced into a flask in vacuo.

35 cm of purified benzene, followed by 6,1 10 mol of compound [222] (representing 6.1X10 mol) were then introduced, whilst continuing to work in vacuo. The medium still contained heterogeneous particles. 5.10 mol of hexamethylcyclotrisiloxane were not introduced. The medium became viscous instantly. The polymerization was stopped after 5 minutes at 20C by introducing acetic acid, which was allowed to react for 5 hours. A hexamethylcyclotrisiloxane polymer was obtained in a yield of 55 percent.

Viscosity of the polymer: [1;]dl/g at 30C in toluene: l1. 6.

M (weight average molecular weight): 7,200,000 (measured by light scattering).

EXAMPLE 31.

Polymerization of B-propiolactone initiated by potassium hydroxide in the presence of compound [222] in a benzene medium.

2.7 mg of KOH(4.8 10 mol) were introduced into a flask in vacuo and dried by heating in vacuo for several hours.

23 cm of benzene were then introduced into the flask in vacuo, followed by 35.5 mg ofcompound [222] (9.4 l0' mol). A solution 6.6.10 mol B-propiolactone in 22 cm" of benzene (thus making a total of 45 cm of benzene) was then introduced at 20C, whilst continuing to work in vacuo. The polymerization was stopped after 24 hours at C by adding methanol. The polymer obtained was precipitated in hexane. It was partially soluble in benzene.

Yield: 61%.

Viscosity of the polymer [1 ]CHCl at 0.65 dl/g.

EXAMPLE 32.

Polymerization of styrene in the presence of the sodium tertiary amylate compound [222] initiator system in a benzene medium.

Sodium tertiary amylate was prepared by heating a solution of 15 cm of benzene, containing 1.8 g of tertiary amyl alcohol and l g of sodium under reflux. After filtering the mixture, the macro-heterobicyclic compound [222] was added in a given ratio and the lower phase of the mixture was removed and used as an initiator solution. 10 mol of sodium tertiary amylate compound [222] were dissolved in cm of benzene. 2X10 mol of styrene were added thereto at ambient temperature. The reaction was complete after 24 hours.

EXAMPLE 33.

Polymerization of styrene in the presence of the system potassium tertiary butylate compound [222] in a benzene medium.

10 mol of potassium tertiary butylate were added to 10 mol of macro-heterobicyclic compound [222] in 30 cm of benzene. The solution obtained was perfectly homogeneous. 2X10 mol of styrene were added at ordinary temperature. The reaction was complete after 48 hours.

In the absence of complexing agent, initiation by alkali metal alcoholates proved completely impossible in the case of styrene.

EXAMPLE 34.

Polymerization of propylene sulphide in the presence of the potassium thiocyanate-compound [222] initiator system, in solution in tetrahydrofuran.

30 cm of previously purified tetrahydrofuran followed by 5.6 mg (l.5X l 0* mol) of 4,7,13,16,21,24-hexaoxa-l,l0- diazabicyclo[8,8,81hexacosane, or compound [222], previously dried in vacuo, were introduced into a flask kept in vacuo and containing 3 mg (3Xl0 mol) of dry potassium thiocyanate KCNS (dried beforehand for one day at 60 under a high vacuum). The solution obtained was homogeneous. The flask was then cooled to C and 2 g (2.7Xl0 mol) of propylene sulphide were introduced by distillation into the reaction medium. The mixture was allowed to return to ordinary temperature. After 72 hours polymerization at 20C in a vacuum of 10 mm of mercury. the medium became very viscous. The thiolate groups at the ends of the polymer chains obtained were then converted into more stable thioether groups by reaction with excess ethyl bromide. The propylene polysulphide thus obtained was recovered by precipitation in methanol and was then dried in vacuo.

Yield: 100%.

M (number average molecular weight) measured by osmometry 2 millions.

M (weight average molecular weight) measured by light scattering: 19 millions.

Without complexing agent no polymerization takes place.

EXAMPLE 35.

Polymerization of isobutene sulphide.

This example describes the use of the compound [22B] as a complexing agent in the presence of potassium acetate as an initiator of the polymerization of isobutene sulphide in benzene.

2.45Xl0 g (representing 2.4Xl0 mol) of potassium acetate were introduced into a flask and dried by heating under a vacuum of 10 mm Hg for half an hour. 37.5 cm of benzene were then introduced, followed by 7.75 mg (representing l.7 l0' mol) of compound [22B]. 2.45 cm (2.2 g) representing 2.5Xl0 mol, of isobutene sulphide were added to this solution by distillation. The reaction was stopped after 19 hours at 20C and precipitated in hexane.

The weight of the dried polymer was 1.56 g, representing a yield of percent. The melting point of the polymer was l88C.

EXAMPLE 36.

Polymerization of isoprene initiated by the system n-butyl-lithium-compound [222] in a benzene medium.

2X10 mol of the macro-heterobicyclic compound [222] were added to 5X10 mol of n-butyl-lithium in 50 cm of benzene. isoprene (4.2 l0 mol) was added to this solution at a temperature of 25C.

The polymerization was extremely rapid and the yield was 100 percent.

The structure of the polyisoprene obtained, deter: mined by nuclear magnetic resonance spectroscopy, NMR, was the following:

Degree of unsaturation: l00% l,4-cis addition: 44% l,4-trans addition: 34% 3,4-addition: 22%

It was found that the presence of the macroheterobicyclic compound considerably changed the structure of the polymer obtained. In fact, in the absence of complexing agent the structure would have been the following:

l,4-cis addition: l,4-trans addition: l2; 3.4-addition: 7%

EXAMPLE 37.

Polymerization of isoprene initiated by the system n-butyl-lithium-compound [222] in a tetrahydrofuran medium.

5X10 mol of compound [222] in 50 cm of tetrahydrofuran, followed by 4.2Xl0 mol of isoprene, were added to 10 mol of n-butyl-lithium. The polymerization temperature was 25C. The polymerization was instantaneous and the yield was percent. The same reaction carried out in the absence of a complexing agent requires 87 seconds for the same degree of conversion.

The micro-structure of the polymer was determined by NMR and gave the following results:

Degree of unsuturation 757: 1.4-addition (total) 5 1571 1.2-addition 277r 3.4-4lddition 587 EXAMPLE 3s.

Polymerization of methyl methacrylate initiated by the system n-butyl-lithium-compound [222] in benzene solution.

l.5 l' mol of n-butyl-lithium was added to mol of compouond [222] in 50 cm of benzene. Then, 2 l0 mol of methyl methacrylate were added at a temperature of 25C. The polymerization time is 24 hours.

EXAMPLE 39.

Copolymerisation of styrene and isoprene initiated by the system t-butyl-lithium-compound [222] in a benzene medium.

6.8 l0' mol of t-butyl-lithium were sublimed onto a cold finger and then dissolved in 90 cm of benzene. 5X10 mol of macro-heterobicyclic compound [222] were added thereto. l.6 l0 mol of styrene were then added thereto and after the addition was complete a further 1.2 10 mol of isoprene were added.

Ratio styrene/isoprene in mols, Calculated: 57/43; Found: 60/40 (the ratio having been determined by NMR).

The reaction was complete after 60 minutes.

EXAMPLE 40.

Polymerization of ethylene oxide initiated by thesystern carbazyl-potassium-compound [222] in tetrahy drofuran.

The compound [222] was introduced into a flask kept under a vacuum and containing a solution of carbazylpotassium in tetrahydrofuran in an amount slightly in excess of the equimolar amount relative to the initiator (ratio [222]/[K 1 1.2), so as to give a concentration of active centres [C] 9.3 l0" mol/- litre.

lnto 30 ml of this solution of carbazyl-potassium complexed by the compound [222], in tetrahydrofuran, was introduced 2.10 mol ethylene oxide (concentration [M] 0.67 mol/l) at C.

After 24 hours at 20 C, the polymerization was stopped by adding methanol to the reaction mixture; the polymer was obtained in a yield of 100 percent.

M (measured by osmometry) 88,000 (theoretical M 89,000).

On the other hand, to achieve comparable yields of poly(ethylene oxide) in the absence of the complexing agent, it was necessary to heat solutions containing about 1 mol/l of ethylene oxide and 10 mol/l of active centres for 4 to 5 days at 40C if only the counter-ion potassium was used. The propagation velocity is considerably increased in the presence of compound [222].

EXAMPLE 41.

Polymerization of cyclohexene sulphide.

This example describes the polymerization of cyclohexene sulphide initiated by living popylene polysulphide which is obtained by polymerization of propylene sulphide initiated by carbazyl-sodium in the presence of the compound [402$] in a tetrahydrofuran medium.

Preparation of propylene polysulphide:

3,3.10 mol of carbazyl-sodium per litre were introduced into 27.8 cm of tetrahydrofuran in a flask in vacuo. 2,3.10 mol of the macro-heterocyclic compound [402$] were added to this solution. 7,7.10 mol of propylene sulphide were then introduced at 20C, whilst continuing to work in vacuo.

Polymerization of cyclohexene sulphide:

2,3.10 mol of cyclohexene sulphide were introduced in vacuo. The polymerization was stopped after 12 hours by the addition of hexane. The yield of polymer was quantitative.

EXAMPLE 42.

Polymerization of propylene sulphide.

This example describes the use of the compounds [221] and [222] as complexing agents in the presence of carbazylsodium and naphthalene-sodium as initiators of the polymerization of propylene sulphide in tetrahydrofuran.

The polymerization was carried out under a vacuum of 10 mm of mercury at 30C.

The value of the complexing agents in the anionic polymerization of propylene sulphide is demonstrated by the following tests:

The propagation velocity of the propylene sulphide in tetrahydrofuran was measured by dilatometry in vacuo, firstly with the counter-ion sodium (Na complexed by the compound [221] and secondly with the counter-ion sodium complexed by the compound [222].

In both cases kinetic measurements were carried out on solutions of seeds or of living polymer consisting of solutions of poly(propylene sulphide) of low degree of polymerization (number average degree of polymerization DP about 250), to which the complexing agent was added in a stoichiometric amount relative to the concentration of Na ions, just before the measurements. These seed solutions were prepared:

firstly, by the action of carbazyl-sodium on a small amount of propylene sulphide in tetrahydrofuran (the solution being intended for use with the compound [221]), and

secondly, by the action of naphthalene-sodium on a small amount of propylene sulphide in tetrahydrofuran (the solution being intended for use with the compound [222]).

The results obtained are collected together in Table V below.

Comparison results obtained with the counter-ion Na (a test with the initiator only, without the complexing agent) and with the counter-ion tetrabutylammonium NBu, (solution prepared from propylene sulphide and fluorenyl-tetrabutyl-ammonium) are also shown.

TABLE V Kinetics of the anionic polymerization of propylene sulphide solvent THF; temperature: 30C) [Cl concentration of active thiolate centres [M] monomer concentration [Vp] propagation velocity Thus, a spectacular increase in the propagation velocity was observed when the counter-ion Na" was complexed by [222]. Further, knowing the propagation constant for free ions in THF at -30C, the theoretical propagation velocity was calculated assuming 100 percent of free ions in the case of the experiment carried out in the presence of [222], and a value below that determined experimentally was found.

Under the concentration conditions of this experiment, not 100 percent of the ions were free and instead there was an equilibrium between complexed pairs of ions and free ions. This thus signifies that the reactivity of the complexed pairs of ions is greater than that of the free ions.

EXAMPLE 43.

Polymerization of methyl methacrylate.

This example describes the action of the marcoheterocyclic compounds [221] and [222] on naphthalene-lithium used as the initiator of the polymerization of methyl methacrylate in a tetrahydrofuran medium.

10 mol of naphthalene-lithium were introduced into 20 cm of tetrahydrofuran in a vacuum chamber. 3.5 l" mol of compound [221] or [222] were added to this green solution. 2 g (representing 2.2Xl0 mol) of methyl methacrylate were then added by distillation to the solution kept at 78C. After minutes, the solution thickened and gelling was complete after 20 minutes. The yield of polymer was 90 percent.

The structure of the polymer determined by NMR was as follows:

lsotactic 6.9%

Heterotatic 38.9%

Syndiotactic 54 EXAMPLE 44.

Polymerization of styrene initiated by the system naphthalene-potassiumcompound [222] in benzene solution.

An initiator solution of potassium-compound [222] in benzene solution was first prepared as described in the earlier Example 25, and naphthalene was then added thereto. The solution immediately turned green, which is the colour characteristic of the system naphthalene-potassium in polar solvents. Ultraviolet spectrophotometric measurements showed an absorption at 325 nm characteristic of this type of initiator.

2X10 mol of styrene were added to the benzene solution of naphthalene-potassium; the solution instantly became red, and the viscosity increased considerably. The reaction was instantaneous.

Yield 100%. Molecular weight: 8.2 l0

EXAMPLES 45 to 60 The examples relate to the polymerization of olefinic monomers, diene monomers, vinyl monomers and arylvinyl monomers in the presence of initiator systems each consisting of a) an aromatic complex of a metal of group 1 or II, in the present instances naphthalenesodium, naphthalene-potassium or an oligomer such as a-methylstyrene-potassium and b) a macroheterobicyclic complexing agent dissolved in a nonpolar or slightly polar solvent. The polymerization conditions and the results are shown in the attached Table EXAMPLE 61.

Preparation of the dimer of 1,1-diphenylethylene initiated by the system potassium-compound [222] in benzene solution.

This example describes the dimerisation of 1,1- diphenylethylene, the polymerization of which does not go beyond the stage of the dimer, for reasons of steric hindrance, and which can act as a bifunctional initiator.

An initiator solution of potassium-compound [222] in benzene solution was prepared as described in the earlier Example 2. 1,1-Diphenylethylene in the liquid phase was introduced into the initiator solution. The dicarbanion dimer of diphenyl-ethylene formed instantly.

The electronic (sic) absorption spectrum of the dicarbanion dimer showed a maximum at 500 nm comparable with that obtained in a polar solvent such as hexamethylphosphorotriamide and with that obtained with the counter-ion Na [222] in the tetrahydrofuran. The solution is stable for 12 hours.

A polymer of molecular weight Mn of 200,000 measured by osmometry for a theoretical molecular weight of 160,000 is obtained.

EXAMPLE 62.

Polymerization of ethylene initiated by the system a-methylstyrene-potassium-compound [222] in a tetrahydrofuran medium.

The living tetramer of a-methylstyrene-potassium is prepared by the action of a-methylstyrene, in tetrahydrofuran, on a film of metallic potassium.

6X10 mol of living tetramer were dissolved in 20 cm of tetrahydrofuran; 6X10 mol of compound [222] were added to this solution.

Ethylene (4X10 mol), previously purified by bubbling through a hot sodium-potassium amalgam, was then introduced into the initiator solution. After 6 hours polymerization, the solution was deactivated by adding methanol. A waxy polymer of molecular weight between 12,000 and 16,000 was obtained with a yield of TABLE VI lnitiator system Ex- Metal Heterocyclic Aromatic com- Solvent Monomer Molecular Notes ample eompound[C](in pound[C](in mol) .[M](in mol) weight No. mol) 45 Na [221 ]=l" Naphthalene Benzene Styrene 7.5 =25C (polymerization [0" 2X10 temperature) 46 Na [22l ]=5 l0 Naphthalene THF lsoprene T= 40C 5 l0 5 l0 47 K [222]=2 l0" Naphthalene Benzene Styrene l.3 l0 T C 2X10" 2X10 48 K [222]=5 l0"' Naphthalene Dioxan Styrene 12x10 T C 5X10" 10" 49 K [Z22]=3Xl0 Naphthalene Benzene lsoprene T 25C l0"" 3X10 Structure:

Unsaturation 9292 l,2-addition 36% l,4-addition 2671 3.4'addition 38% 50 K [222]=3 l0 Naphthalene Benzene Methyl meth lsotatic 8% 10' acrylate Heterotactic 39% 2X10 Syndiotactic 53% 5l K [222]=2Xl0 Naphthalene Benzene Butadiene 6,000 T 25C 2X10" 1O" 52 K [222]=2Xl0" Naphthalene Dioxan Butadiene 10,000 T -20C 2X10 10' 53 K [222 ]=2.5Xl0- Naphthalene= Toluene Styrene T 40C l0 10" 54 K [222]=l0" a-methylstyrene Benzene lsoprene 25000 T 25C 10' 3x10 55 K [222]=5Xl0 a-methylstyrene Benzene lsoprene DP s 5 T 25 =5 l0" 3Xl0' 56 K [222]=5 l0 a-methylstyrene Benzene Butadiene= DP l0 T =25C 5 (lO 1O 57 K [222]==5X10" a-methylstyrene Benzene Ethylene Polymer of T =lOC X l0 10' very high Insoluble in customary molecular solvents weight 58 Na [222]=3 l0 Naphthalene Benzene Methyl T 25C 3X10 methacry- Yield: late 2 l0 59 Na [222]=3Xl0 Naphthalene Benzene lsoprene T 25C 3X10 2X10" Yield: 30% 60 K [222]=3Xl0 Naphthalene THF Methyl T 25C 3X10' methacry- Yield: l00% late 2Xl0' 61 Li [222]=3Xl0' Naphthalene Benzene Methyl T 25C 3X10 methacrylate Yield I00 7r ZXIO What we claim is: solvent medium in the presence of an anionic initiator 1. A process for the polymerization or co ol and of a macro-heterocychc complexmg agent of the ization of of at least one monomer containing ethylenic general formula I R N sm, 1 \A/i \Ain/ 1 unsaturation which comprises polymerizing or copolyin which:

R is a hydrogen atom or a hydrocarbon group or an alkoxycarbonyl group, or the two R together can unsaturation in a non-polar or slightly polar organic form a group of the general formula:

merizing at least one monomer containing ethylenic D/A A----N -A zg \n \A D D/ P A is a hydrocarbon group, R D is an oxygen or sulphur atomor a hydrocarbon group, with the proviso that at least two of the D groups are oxygen atoms or sulphur atoms and that if R is a hydrogen atom, a hydrocarbon group or h r R i a hydrocarbon radical.

an alkoxycarbonyl r one f th t 1) groups 4. A process according to claim 1, wherein the macis oxygen or sul hur d th other i oxygen, d ro-heterocyclic complexing agent has the formula:

/ GHQ-(31% /CH2-CH%\ I I R N\ i N R 0 CH -CH CH -CHJ n and p are integers from 1 to 3 and m is 2 or 3. in which the two substituents R, together represent 2. A process according of claim 1 wherein the macroone of the following chain links forming a third bridge heterocyclic complexing agent has the fonnula: between the two nitrogen atoms of the molecule:

$o/ --CH CH -EO CH CH A 1\/ -CH CH {S CH CH5 A A A \O CH CH {CH CH CH N-- A A A N s p or 0 0 A -CH CH -O (I) CH CH CH CH 0 0 N A s A s.- A- on 0 0 A A \A/ --CH CH O 0 CH CH A- o A 0 A N--A-- o A- -s A N orso S O or -CH -CH {0 CH 4311 p A A A O O N--A ---S-A---- S------ --N CH -CH S CH -CH N 2 2\EO/ 2 2m N O c11 mug? \c in which A, m, n and p are as defined in claim 1. n

3. A process according to claim 2 wherein A is -CH -CHR,

where n and p and m are as defined in claim 1.

5. A process according to claim 4, wherein the macro-heterocyclic complexing agent has the formula N CH2 mu E -CH -CII N n CH2 -CH2 CH -CH in which n and p and m are as defined in claim 1.

6. A process according to claim 5 wherein the macroheterocyclic complexing agent is bicyclo[5,5,8]eicosane,

l,lO-diaza-4,7,1 3, l 6,2 l -pentaoxabicyclo[8,8,5]tricosane,

l ,lO-diaza-4,7,l 3, 16,21 ,24-hexaoxa-bicyclo[8,8,8-

]hexacosane, or l,13-diaza-4,7,l0,l6,l9,24,27-heptaoxabicyclo[8,8,l l]nonacosane.

7. A process according to claim 4, wherein the complexing agent is 1,lO-diaza-l3,l6,21,24-tetraoxa-bicyclo[8,8,8]hexacosane.

8. A process according to claim 4, wherein the complexing agent is l,l0-diaza-4,7,l3,16,21,26-hexaoxabicyclo[8,8,0]heptacosane.

9. A process according to claim 4, wherein the complexing agent is l,l0-diaza-4,7,l3,l6,2l ,24-hexaoxa- 5,5-benzobicyclo[8,8,8]hexacosane.

10. A process according to claim 4, wherein the complexing agent is l,lO-diaza-4,7,l3,l6-tetraoxa-2l ,24- dithia-bicyclo[ 8,8,8 ]hexacosane.

1 l. A process according to claim 4, wherein the complexing agent is 1,7,16,22-tetraaza- 4,10,] 3,l9,25,28,33,36,4l ,44-decaoxatricyclo[2O.8" .8" .8 ]hexatetra-contane.

12. A process according to claim 1, wherein the anionic initiator is:

a metal of group I or II,

a hydroxide of a metal of group I an alcoholate of a metal of group I or [I an amide of a metal of group I or II of the type wherein R and R are hydrogen or an alkyl, cycloalkyl or aryl radical and M is a metal of group I or II, n being the valency of the metal a compound MX, wherein M is a metal of group I or II or of the corresponding subgroup,

n is the valency of the metal, and X is a thiocyanate or acetate group a monofunctional or difunctional organo-metallic derivative RM wherein M is a metal of group I or ll and R is an alkyl, cycloalkyl or aryl radical, or

an aromatic complex of a metal of group I or II, or

a living monofuncti'onalor difunctional oligomer or polymer.

13. A process according to claim 12, wherein the anionic initiator is v metallic lithium'sodium, potassium caesium,

potassium hydroxide,

an alkali metal t-butylate, t-amylate or n-amylate,

potassium thiocyanate, potassium bromide and potassium acetate,

n-butyl-lithium, t-butyl-lithium, carbazyl-potassium and carbazyl-sodium, naphthalene-sodium, naphthalene-lithium naphthalene-potassium, or a-methylstyrene-sodium or potassium, 1,l-diphenylethylene-sodium or potassium, poly(propylene sulphide) sodium and polystyrene-lithium.

14. A process according to claim 1, wherein the nonpolar or slightly polar organic solvent is an organic solvent having a dielectric constant not exceeding 10 under normal temperature and pressure conditions.

15. A process according to claim 14, wherein the organic solvent is a linear or cyclic saturated hydrocarbon,

an aromatic hydrocarbon, or

a linear or cyclic ether.

16. A process according to claim 15, wherein the organic solvent is hexane, heptane, cyclohexane, benzene, toluene, dioxane, diethylether, dimethoxyethane, dimethoxymethane, tetrahydrofuran or tetrahydropyran.

17. A process according to claim 1, wherein the complexing agent is present in at least equimolecular amount, relative to the anionic initiator.

18. A process according to claim 1 wherein the initiator is in a solution which is prepared by reacting the anionic initiator with the complexing agent in a non-polar or slightly polar solvent medium, and then the monomer to be polymerised is added thereto.

19. A process according to claim 8, wherein the initiator solution is prepared by adding the complexing agent to a metal of group I, in the form of a film or in finely divided form, in a non-polar or slightly polar organic solvent, so as to form a solution of the metal, at ambient temperature or below.

20. A process according to claim 18, wherein the solution of initiator is prepared by adding the complexing agent to an alkali metal in a non-polar or slightly polar organic solvent medium so as to form a solution of the said metal, and then adding thereto an aromatic hydrocarbon, to form an aromatic hydrocarbon-alkali metal complex.

21. A process according to claim 20, wherein the aromatic hydrocarbon is biphenyl, naphthalene, phenanthrene, pyrene or anthracene.

22. A process according to claim 19, wherein the metal is sodium, potassium or caesium, the complexing agent is l,l0-diaza-4,7,l3,16,2l-pentaoxabicyclo[8,8,5]tricosane or 1,lO-dia7.a-4,7,l3,l6,2l,24- hexaoxa-bicyclo[8,8,8 Ihexacosane and the organic solvent is benzene or toluene.

23. A process according to claim 20, wherein the metal is sodium, potassium or lithium, the complexing agent is 1,lO-diaza-4.7,l3,l6,2l,24-hexaoxa-bicyclo[8,8,8]hexacosane, the aromatic hydrocarbon is naphthalene and the organic solvent is benzene or toluene.

and

rx-methylstyrenetiator is potassium acetate, te complexing agent is l, l0- ,-diaza-4,7,l 3,16,21 ,24-hexaoxa-5,6-benzo-bicyclo[8,8,8]hexacosane and the organic solvent is tetrahydrofuran.

27. A process according to claim 18, wherein the anionic initiator is wmethylstyrene tetramer-potassium, the complexing agent is 1,lO-diaza-4,7,l3,16,21,24- hexaoxa-bicyclo[8,8,8]hexacosane and the organic solvent is tetra-hydrofuran or benzene. 

1. A PROCESS FOR THE POLYMERIZATION OR COPOLYMERIZATION OF OF AT LEAST ONE MONOMER CONTAINING ETHYLENIC UNSATURATION WHICH COMPRISES POLYMERIZING OR COPOLYMERIZING AT LEAST ONE MONOMER CONTAINING ETHYLENIC UNSATURATION IN A NON-POLAR OR SLIGHTLY POLAR ORGANIC SOLVENT MEDIUM IN THE PRESENCE OF AN ANIONIC INITATOR AND OF A MACRO-HETEROCYCLIC COMPLEXING AGENT OF THE FORMULA I
 2. A process according of claim 1 wherein the macro-heterocyclic complexing agent has the formula:
 3. A process according to claim 2 wherein A is -CH2-CHR-, -CH2-CHR-CH2-, -CHR-CH2-CH2-, or
 4. A process according to claim 1, wherein the macro-heterocyclic complexing agent has the formula:
 5. A process according to claim 4, wherein the macro-heterocyclic complexing agent has the formula
 6. A process according to claim 5 wherein the macro-heterocyclic complexing agent is 1,10-diaza-4,7,13,18-tetraoxa-bicyclo(5,5,8)eicosane, 1,10-diaza-4,7,13,16,21-pentaoxa-bicyclo(8,8,5)tricosane, 1,10-diaza-4,7,13,16,21,24-hexaoxa-bicyclo(8,8,8)hexacosane, or 1,13-diaza-4,7,10,16,19,24,27-heptaoxa-bicyclo(8,8,11) nonacosane.
 7. A process according to claim 4, wherein the complexing agent is 1,10-diaza-13,16,21,24-tetraoxa-bicyclo8,8,8)hexacosane.
 8. A process according to claim 4, wherein the complexing agent is 1,10-diaza-4,7,13,16,21,26-hexaoxa-bicyclo(8,8,0)heptacosane.
 9. A process according to claim 4, wherein the complexing agent is 1,10-diaza-4,7,13,16,21,24-hexaoxa-5,5-benzobicyclo(8,8, 8)hexacosane.
 10. A process according to claim 4, wherein the complexing agent is 1,10-diaza-4,7,13,16-tetraoxa-21,24-dithia-bicyclo(8,8, 8)hexacosane.
 11. A process according to claim 4, wherein the complexing agent is 1,7,16,22-tetraaza-4,10,13,19,25,28,33,36,41,44-decaoxa -tricyclo(20.81,22.81,22.87,16)hexatetra-contane.
 12. A process according to claim 1, wherein the anionic initiator is: a metal of group I or II, a hydroxide of a metal of group I an alcoholate of a metal of group I or II aN amide of a metal of group I or II of the type
 13. A process according to claim 12, wherein the anionic initiator is metallic lithium sodium, potassium caesium, potassium hydroxide, an alkali metal t-butylate, t-amylate or n-amylate, potassium thiocyanate, potassium bromide and potassium acetate, n-butyl-lithium, t-butyl-lithium, carbazyl-potassium and carbazyl-sodium, naphthalene-sodium, naphthalene-lithium and naphthalene-potassium, or Alpha -methylstyrene-sodium or Alpha -methylstyrene-potassium, 1,1-diphenylethylene-sodium or potassium, poly(propylene sulphide) sodium and polystyrene-lithium.
 14. A process according to claim 1, wherein the non-polar or slightly polar organic solvent is an organic solvent having a dielectric constant not exceeding 10 under normal temperature and pressure conditions.
 15. A process according to claim 14, wherein the organic solvent is a linear or cyclic saturated hydrocarbon, an aromatic hydrocarbon, or a linear or cyclic ether.
 16. A process according to claim 15, wherein the organic solvent is hexane, heptane, cyclohexane, benzene, toluene, dioxane, diethylether, dimethoxyethane, dimethoxymethane, tetrahydrofuran or tetrahydropyran.
 17. A process according to claim 1, wherein the complexing agent is present in at least equimolecular amount, relative to the anionic initiator.
 18. A process according to claim 1 wherein the initiator is in a solution which is prepared by reacting the anionic initiator with the complexing agent in a non-polar or slightly polar solvent medium, and then the monomer to be polymerised is added thereto.
 19. A process according to claim 8, wherein the initiator solution is prepared by adding the complexing agent to a metal of group I, in the form of a film or in finely divided form, in a non-polar or slightly polar organic solvent, so as to form a solution of the metal, at ambient temperature or below.
 20. A process according to claim 18, wherein the solution of initiator is prepared by adding the complexing agent to an alkali metal in a non-polar or slightly polar organic solvent medium so as to form a solution of the said metal, and then adding thereto an aromatic hydrocarbon, to form an aromatic hydrocarbon-alkali metal complex.
 21. A process according to claim 20, wherein the aromatic hydrocarbon is biphenyl, naphthalene, phenanthrene, pyrene or anthracene.
 22. A process according to claim 19, wherein the metal is sodium, potassium or caesium, the complexing agent is 1,10-diaza-4,7,13,16,21-pentaoxa-bicyclo(8,8,5)tricosane or 1,10-diaza-4,7, 13,16,21,24-hexaoxa-bicyclo(8,8,8) hexacosane and the organic solvent is benzene or toluene.
 23. A process according to claim 20, wherein the metal is sodium, potassium or lithium, the complexing agent is 1,10-diaza-4,7,13,16,21,24-hexaoxa-bicyclo(8,8,8)hexacosane, the aromatic hydrocarbon is naphthalene and the organic solvent is benzene or toluene.
 24. A process according to claim 18, wherein the initiator is potassium hydroxide, the complexing agent is 1,10-diaza-4,7,13, 16,21,24-hexaoxa-bicyclo(8,8,8)hexacosane and the organic solvent is tetrahydrofuran or benzene.
 25. A process according to claim 18 wherein the initiator is potassium thiocyante, the complexing agent is 1,10-diaza-4,7,13, 16,21,24-hexaoxa-bicyclo(8,8,8)hexacosane and the solvent is tetrahydrofuran.
 26. A process according to claim 18, wherein the initiator is potassium acetate, te complexing agent is 1,10,-diaza-4,7,13,16, 21,24-hexaoxa-5,6-benzo-bicyclo(8,8,8) hexacosane and the organic solvent is tetrahydrofuran.
 27. A process according to claim 18, wherein the anionic initiator is Alpha -methylstyrene tetramer-potassium, the complexing agent is 1,10-diaza-4,7,13,16,21,24-hexaoxa-bicyclo(8, 8,8) hexacosane and the organic solvent is tetra-hydrofuran or benzene. 